Partial flap landings aren't too common in general aviation, but here are some reasons you might decide to not use your full flap setting.

1) Flap Failure

If your flaps fail to extend, you will obviously be forced to make a landing without them. This scenario is fairly straight forward, as there is no decision making for you. Just remember to increase your approach and landing speeds. Typically, those speeds are listed in your POH or AFM.

2) Icing Conditions

If you've encountered icing at any point during your flight, many manufacturers will recommend that you land with a partial flap setting. As usual, you should check the POH specific to your plane for guidance. But why do they recommend that you don't extend full flaps in icing conditions?

It usually has less to do with the wings, and more to do with your horizontal stabilizer. If ice is built up on your horizontal stabilizer, then extending your flaps could change the airflow around the tail causing a tail stall.

3) Strong Crosswinds

Some popular training aircraft POHs (like the Cessna 172) recommends that you shouldn't use full flaps when you are landing in strong crosswinds. Why?

Flaps will provide you with more lift, allowing you to fly at lower airspeeds. The lower your airspeed is, the less effective your controls become. So in a strong crosswind, using partial flaps increases your final approach speed, and in turn, increases your control's effectiveness (especially your rudder), allowing you to make the perfect crosswind landing.

4) Instrument Approaches

As you transition from instrument to visual conditions, adding flaps can destabilize your approach.

Typically if you are below 500 feet AGL when you visually identify the airport environment, it's best to keep your current configuration. As with any partial-flap landing, don't forget to adjust your landing speeds!

Are there any other situations where you use partial flaps? Tell us in the comments below.